.\" #
.\" # Copyright (c) 2014, Juniper Networks, Inc.
.\" # All rights reserved.
.\" # This SOFTWARE is licensed under the LICENSE provided in the
.\" # ../Copyright file. By downloading, installing, copying, or 
.\" # using the SOFTWARE, you agree to be bound by the terms of that
.\" # LICENSE.
.\" # Phil Shafer, July 2014
.\" 
.Dd December 4, 2014
.Dt LIBXO 3
.Os
.Sh NAME
.Nm xo_parse_args , xo_set_program
.Nd detect, parse, and remove arguments for libxo
.Sh LIBRARY
.Lb libxo
.Sh SYNOPSIS
.In libxo/xo.h
.Ft int
.Fn xo_parse_args "int argc" "char **argv"
.Ft int
.Fn xo_set_program "const char *name"
.Sh DESCRIPTION
The
.Fn xo_parse_args
function is used to process command-line arguments.
.Nm libxo
specific
options are processed and removed
from the argument list so the calling application does not
need to process them.
If successful, a new value for argc is returned.
On failure, a message it emitted and -1 is returned.
.Bd -literal -offset indent
    argc = xo_parse_args(argc, argv);
    if (argc < 0)
        exit(EXIT_FAILURE);
.Ed
.Pp
Following the call to
.Fn xo_parse_args ,
the application can process the remaining arguments in a normal manner.
.Pp
.Nm libxo
uses command line options to trigger rendering behavior.
The following options are recognised:
.Pp
.Bl -tag -width "--libxo"
.It
\-\^\-libxo <options>
.It
\-\^\-libxo=<options>
.It
\-\^\-libxo:<brief-options>
.El
.Pp
Options is a comma-separated list of tokens that correspond to output
styles, flags, or features:
.Pp
.Bl -tag -width "12345678"
.It Sy "Token   Action"
.It Dv dtrt
Enable "Do The Right Thing" mode
.It Dv html
Emit HTML output
.It Dv indent=xx
Set the indentation level
.It Dv info
Add info attributes (HTML)
.It Dv json
Emit JSON output
.It Dv keys
Emit the key attribute for keys (XML)
.It Dv log-gettext
Log (via stderr) each
.Xr gettext 3
string lookup
.It Dv log-syslog
Log (via stderr) each syslog message (via
.Xr xo_syslog 3 )
.If Dv no-humanize
Ignore the {h:} modifier (TEXT, HTML)
.It Dv no-locale
Do not initialize the locale setting
.It Dv no-retain
Prevent retaining formatting information
.It Dv no-top
Do not emit a top set of braces (JSON)
.It Dv not-first
Pretend the 1st output item was not 1st (JSON)
.It Dv pretty
Emit pretty-printed output
.It Dv retain
Force retaining formatting information
.It Dv text
Emit TEXT output
.If Dv underscores
Replace XML-friendly "-"s with JSON friendly "_"s e
.It Dv units
Add the 'units' (XML) or 'data-units (HTML) attribute
.It Dv warn
Emit warnings when libxo detects bad calls
.It Dv warn-xml
Emit warnings in XML
.It Dv xml
Emit XML output
.It Dv xpath
Add XPath expressions (HTML)
.El
.Pp
The
.Dq brief-options
are single letter commands, designed for those with
too little patience to use real tokens.
No comma separator is used.
.Bl -column "i<num>"
.It Sy "Token   Action"
.It "H      " "Enable HTML output (XO_STYLE_HTML)"
.It "I      " "Enable info output (XOF_INFO)"
.It "i<num> " "Indent by <number>"
.It "J      " "Enable JSON output (XO_STYLE_JSON)"
.It "P      " "Enable pretty-printed output (XOF_PRETTY)"
.It "T      " "Enable text output (XO_STYLE_TEXT)"
.It "W      " "Enable warnings (XOF_WARN)"
.It "X      " "Enable XML output (XO_STYLE_XML)"
.It "x      " "Enable XPath data (XOF_XPATH)"
.El
.Pp
The
.Fn xo_set_program
function sets name of the program as reported by
functions like
.Fn xo_failure ,
.Fn xo_warn ,
.Fn xo_err ,
etc.
The program name is initialized by
.Fn xo_parse_args ,
but subsequent calls to
.Fn xo_set_program
can override this value.
.Pp
Note that the value is not copied, so the memory passed to
.Fn xo_set_program
(and
.Fn xo_parse_args )
must be maintained by the caller.
.Pp
.Sh SEE ALSO
.Xr xo_emit 3 ,
.Xr libxo 3
